The invention relates to image decoding, and more particularly, to systems and methods for decoding large images.
Portable electronic devices such as mobile phones, personal digital assistants (PDAs), digital cameras, or similar, are typically equipped with still image decoders to decode compressed images such as Joint Photographic Experts Group (JPEG) images, but have relatively small screens for display of the decoded images. When viewing an image displayed on the small screen, the user prefers to zoom-in a particular portion of the image via keys on a keypad for detailed viewing.
When a user selects a portion of an image, an image decoding method fully decodes the entire image and displays the selected portion of the image on a screen. Decoding non-displayed portions of an image using this image decoding method, however, may be excessively time consuming.
Another image decoding method generates a thumbnail image (i.e. a reduced image) corresponding to an image, enlarges the selected portion of the thumbnail image and displays the enlarged image on a screen. This image decoding method, however, may offer reduced image quality, due to the enlarging process.